<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style type="text/css" src="{{ url_for('static',filename='1.css') }}"></style>
</head>
<body>
{% block head %}
    this is head
{% endblock %}
{% block content %}
    this is content
{% endblock %}
{% block footer %}
    this is footer
{% endblock %}
</body>
</html>